/*
 * Copyright (C) 2009-2010 Geometer Plus <contact@geometerplus.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

package org.geometerplus.fbreader.library;

import java.util.HashMap;

public final class Tag {
    private static final HashMap<Tag, Tag> ourTagSet = new HashMap<Tag, Tag>();

    public static Tag getTag(Tag parent, String name) {
        if (name == null) {
            return parent;
        }
        name = name.trim();
        if (name.length() == 0) {
            return parent;
        }
        Tag tag = new Tag(parent, name);
        Tag stored = ourTagSet.get(tag);
        if (stored != null) {
            return stored;
        }
        ourTagSet.put(tag, tag);
        return tag;
    }

    public final Tag Parent;
    public final String Name;

    private Tag(Tag parent, String name) {
        Parent = parent;
        Name = name;
    }

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof Tag)) {
            return false;
        }
        Tag t = (Tag) o;
        return (Parent == t.Parent) && Name.equals(t.Name);
    }

    @Override
    public int hashCode() {
        return (Parent == null) ? Name.hashCode() : Parent.hashCode() + Name.hashCode();
    }
}
